Search

Nine Ge−Fe carbonyl cluster compounds are prepared via ionic liquids‐based synthesis. This includes the novel compounds [EMIm][Fe(CO)3I(GeI3)], [EHIm][Fe(CO)3I(GeI3)], [BMIm][GeI2{Fe(CO)4}2(μ‐I)][AlCl4]2, [GeI2{Fe(CO)4}2(μ‐I)][Fe(AlBr4)3], [BMIm]2[(FeI2)0.75{Fe(CO)2I(GeI3)2}2], and [EHIm][Fe(CO)4(GeI2)2Fe(CO)3GeI3] as well as the previously reported compounds (Fe(CO)4(GeI3)2, FeI4{GeI3Fe(CO)3}2, and Ge12{Fe(CO)3}8(μ‐I)4 (EMIm: 1‐ethyl‐3‐methylimidazolium, EHIm: 1‐ethylimidazolium, BMIm: 1‐butyl‐3‐methylimidazolium). With this series of compounds, a comparison of synthesis conditions and structural features is possible and, for instance, allows correlating the composition and structure of the respective Ge−Fe carbonyl cluster compounds with the type and acidity of the ionic liquid. With [EMIm][{GeI3}2Fe(CO)3I], moreover, we can exemplarily show the thermal decomposition as a single‐source precursor in the ionic liquid, resulting in bimetallic Ge−Fe nanoparticles with small size and narrow size distribution (7.0±1.4 nm). [ABSTRACT FROM AUTHOR]

Microemulsions (MEs) are ideal for obtaining high-quality inorganic nanoparticles. As thermodynamically stable systems with a nanometer-sized droplet phase that serves as a nanoreactor, MEs have obvious advantages for the synthesis of nanoparticles. MEs also have disadvantages, such as their complexity as multicomponent systems, the low amount of obtainable nanoparticles, their limited thermal stability, the fact that hydrolyzable or oxidizable compounds are often excluded from synthesis, the partly elaborate separation of nanoparticles, as well as the removal of surface-adhered surfactants subsequent to synthesis. This Review presents some strategies to further expand the options of ME-based synthesis of inorganic nanoparticles. This comprises the crystallization of nanoparticles in 'high-temperature MEs', the synthesis of hollow nanospheres, the use of hydrogen peroxide or liquid ammonia as the polar droplet phase, and the synthesis of base metals and nitrides in MEs. [ABSTRACT FROM AUTHOR]

AgSCN nanoparticles were prepared via a water-in-oil microemulsion approach, using KSCN and AgNO3 as starting materials. The as-prepared AgSCN nanoparticles are readily crystalline, exhibit a uniform spherical shape, and have a mean diameter of 25 nm. Scanning electron microscopy (SEM) and dynamic light scattering (DLS) confirm particle size and size distribution. X-ray powder diffraction (XRD) and Fourier-transform infrared spectroscopy (FT-IR) prove the phase composition and purity. The particle size can be varied in a range of 25 and 40 nm (according to electron microscopy) by variation of the concentration of AgNO3 (i.e., 2 mL of 0.1 to 0.5 M AgNO3 solution). Optical spectroscopy (UV/Vis) indicates an optical band-gap of 3.78 eV without a size-depending shift at this specific particle size. The microemulsion approach can be extended to obtain further nanoscaled thiocyanates like CuSCN, AuSCN, Hg(SCN)2, and Pb(SCN)2. [ABSTRACT FROM AUTHOR]

Abstract: Monodisperse, indium doped zinc oxide (IZO) nanoparticles were prepared via the polyol-mediated synthesis and incorporated into regular and inverted poly-(3-hexylthiophene-2,5-diyl) and [6,6]-phenyl C61-butyric acid methyl ester organic photovoltaic devices as buffer layers between the active layer and the cathode. Efficient hole blocking at the particle buffer layers leads to an enhanced open-circuit voltage of the solar cells. This effect is even more pronounced for inverted device architectures. Device degradation studies revealed a solar cell performance reduction upon sample exposition to ambient atmosphere. However, this degradation is fully reversible under UV illumination. In addition, the n-doped IZO particles form suitable charge carrier transport layers for an efficient recombination in an intermediate recombination zone in tandem solar cells. Accordingly we have fabricated fully solution-processed tandem solar cells and investigated their optoelectronic properties. [ABSTRACT FROM AUTHOR]